The invention relates generally to the generation of energy. Of particular interest to the invention is the generation of electrical energy.
The conventional methods used until now for the production of electrical energy in thermal power plants which operate on a coal or oil basis consist in that the coal or fuel oil serving as the energy source is combusted beneath steam boilers. The steam obtained in this manner is then expanded in steam turbines which are coupled with electrical generators.
In these methods, the sulfur compounds contained in the coal or fuel oil are converted into sulfur dioxide during the combustion period. Due to the ever stricter regulations governing environmental pollution, the sulfur dioxide can no longer be simply discharged into the atmosphere through the stacks provided for the combustion gases. However, the removal of the sulfur dioxide from the combustion gases poses great difficulties, particularly for large power plants. Although great efforts have been expended in this direction, the problem of removing sulfur dioxide from the combustion gases has not been satisfactorily solved to date.
In view of this, there has recently been discussed the possibility of first converting the coal or fuel oil used for the electrical generation into a fuel gas by gasification (partial oxidation) in a gasifying apparatus arranged upstream of the power plant and then using this fuel gas as an energy source in the power plant. The reason is that the sulfur compounds contained in the coal or fuel oil are not transformed into sulfur dioxide during gasification but, rather, are transformed primarily into hydrogen sulfide. The latter may be removed from the fuel gas produced by the gasification in a relatively simple manner using suitable physical and chemical wash processes so that the fuel gas may be conveyed to the power plant in a condition where it is largely free of sulfur.
Although the procedure just outlined apparently holds promise for overcoming the difficulties mentioned earlier, it has not yet become possible to apply this in a satisfactory manner.